Measurement and discrete element simulation of a fixed-obstacle disturbed rapid granular chute flow

We describe the experimental measurements and discrete element simulations of steady rapid granular chute flows disturbed by a small fixed semi-cylindrical obstacle. The flow chute has a width of 5 cm, a length of 150 cm, an inclination of 30°, with an obstacle installed at approximately the center of the chute. The steady disturbed flow has a region that exhibits substantial but smooth changes in flow characteristics, like a very diffused weak shock. Our measurements include the streamwise flow depth, velocity, and flux-averaged solid fraction. We compare the velocity profile from far upstream of the disturbed flow region with the prediction of an analytical solution based on the kinetic theory. We construct a control volume method to calculate the force exerted by the obstacle on the flow based on the influenced distance of the obstacle. Comparison showed satisfactory agreement between the measured obstacle forces with the discrete element simulations.